Rip currents - fast moving, narrow channels of water that can drag swimmers out to sea - are not becoming more frequent or more vicious.

But our changing climate is making them more unpredictable, according to Dr Simon Boxall, an oceanographer at the University of Southampton.

Video:How To Survive A Rip Tide

Dr Boxall told Sky News: "Climate change means not just more winter storms, but more summer storms as well, so you have an ever moving topography.

"Rip currents need an escape and so they work on the topography of the sea floor.

"Now if you get big storms, the storms can change the topography completely, they can move a sand bar a kilometre overnight. That's how powerful they are.

"And so because you get these moving sandbars every time you get a big storm, it means predicting where the rip currents are likely to take place becomes very difficult."

The RNLI have added Camber Sands to its "community life-saving plan", recognising that a previously unremarkable stretch of beach has become more dangerous. It has also introduced a temporary RNLI lifeguard service.

Video:Push For Lifeguards At Camber Sands After Five Deaths

Speaking on the beach, Darren Lewis, senior lifeguard manager at the RNLI, told Sky News: "Generally, storms happen in the winter so as we approach the summer season, we will see whether things have shifted around and new hazards have presented themselves.

"So it should be always an ongoing process and then you should look to build in the control measures, whether they be lifeguards, whether they be public rescue equipment, signage, that interaction with the public to let them know what's happening."

Camber Sands is notable for its strong rip currents.

Breaking waves push water towards land; rip currents form when this water finds a channel to flow quickly back out to sea, between sandbars, for example.

These currents can travel up to two-and-a-half metres per second - faster than any human swimmer.

But they are narrow so can be escaped by swimming parallel to the shore.

Tom Packman, a deckhand on a scuba diving boat operating in the waters around Camber Sands, told Sky News that riptides "could move from side to side, and the sand bars can shift which then might change the rip to a different place".

He said: "You may come down here three or four times and be absolutely fine, and then on the fifth time it can all change and you can be caught out by it."